Genus: Test variable, chitinoid; binucleate (Illustrated Guide, 1985).
Group: Discoides (Test flattened; height < 1/2 greatest diam.)
Species: Diam. 90-150 μm, height 25-30 μm; pseudostome, round, 30-40 μm; with or without ring of pores (Illustrated Guide, 1985).
->> Description at WPRNO Google Image Search
A. discoides
test 132 μm
Uruguay, 1999
A. discoides
test 120 μm
Omine-numa
Tsukiyono
Gunma, 2003
A. discoides
test 110 μm
Uruguay, 1999
A. discoides
test 165 μm
Obihiro-Hasshonochi
Obihiro
Hokkaido, 2005
A. discoides
test 95 μm
Uruguay, 1999
A. discoides
test 83 μm
Japan, 199?